The figure is not drawn to scale. Three pentagons G, H and J are arranged as shown in the figure. The area of Pentagon G is ⁴₅ the area of Pentagon H. The area of Pentagon H is ¹₇ the area of Pentagon J.
(a) Find the ratio of the area of Pentagon G to the area of Pentagon J.
(b) ³₄ of Pentagon G is shaded. What fraction of the whole figure is not shaded?

G	H	J
4x1	5x1
	1x5	7x5
4 u	5 u	35 u

(a)
Area of Pentagon H is the repeated identity. Make the area of Pentagon H the same. LCM of 5 and 1 is 5.

Pentagon G : Pentagon J
4 : 35

(b)
Shaded part of Pentagon G
= ³₄ x 4 u
= 3 u

Unshaded part of Pentagon G
= 4 u - 3 u
= 1 u

Unshaded part of Pentagon J
= 35 u - 3 u
= 32 u

Total figure unshaded
= 32 u + 1 u
= 33 u

Total figure
= 35 u + 1 u
= 36 u

Fraction of the whole figure that is unshaded
= ³³₃₆
= ¹¹₁₂

Answer(s): (a) 4 : 35; (b) ¹¹₁₂